High-Resolution Terahertz Spectroscopy by a Compact Radiation Source Based on Photomixing with Diode Lasers in a Photoconductive Antenna
We demonstrate generation of continuous-wave terahertz radiation and its application to molecular spectroscopy. The radiation source is based on the photomixing of two diode laser beams in a low-temperature-grown GaAs photoconductive antenna, which offered output power of several tens of nanowatts at frequencies up to 2 THz with its long term frequency stability being about 5 MHz. The pure rotational spectra of CH3CN and isotopomers of CO were measured with this source, and 1% of absorption was clearly detected with a simple amplitude modulation technique. This indicates that the present system has a potential capability for high-resolution and high-sensitivity molecular spectroscopy. Copyright 1998 Academic Press. Copyright 1998Academic Press
Matsuura
S
Kansai Advanced Research Center, Communications Research Laboratory, M. P. T., Iwaoka, Nishi-ku, Kobe, 651-24, Japan
Tani
M
Abe
H
Sakai
K
Ozeki
H
Saito
S